My suggestion:

Patent it. Quickly.

That's a simple and elegant idea. It would also be perfect for igniting the upper stages, eh?

We used to fly head-end Kosdon East motors. They weren't as elegant as Edward's, but they worked...

I'm going to be doing airstarts, so in effect a 2nd stage. I didn't want to have to have a way to hold the igniters up at the top of the core and didn't want to swiss cheese the back end of my rocket.

Edward

As long as you've got a good thick anodize, you shouldn't have to worry about incidental contact between the plug and the closure, because it will happen, even with perfect o-rings.

You could take it a step further and do the plug out of ceramic with the brass contact threaded all the way through it. If the threads needed additional sealing, there are some VERY high temp ceramic epoxies out there.

-Ken

The anodizing will help to keep the contact down. I'm planning on machining the ends so that there is .015-.020 between the plug and the wall on each side.

I'm trying to avoid drilling a hole all the way through the plug and having to go back and seal it. My first few ideas were along those lines and then I decided I didn't want to have another point of failure, even if the chance was low.

Edward

Unfortunately, if you publish it before you apply for the patent, your patent rights are pretty much shot.

I've long thought about head-end ignition, but the only idea I've come up with involves drilling two holes for conductors through the forward closure and then filling them with high temp epoxy surrounding the conductors. The holes would have to either taper or be stepped to be larger on the inside face of the closure than on the outside to prevent pressure from blowing the plugs out. I believe I still have 38mm AT closure I drilled out to try it somewhere around here.

Warren